Production of divided metals.



UNITED smrgs PATENT orrron.

FRITZ BLAU, F BERLIN, GERMANY, ASSIGNOR, BY MESN E ASSIGNMENTS, TO GENERAL- ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

PRODUCTION OF J JIVIDED METALS.

Patented Feb. 28, 1911. Application filed September 14, 1906. Serial No. 334,561.

No Drawing.

Specification ofLetters lPatent.

' To all whom it may concern: always if the product is flooded with ordi- Be it known that I, F nrrz BLAU, chemist, a subject of the Emperor of Austriadlungary, and a resident of Berlin, Germany, have invented certain new and useful lmprovemcnts in the Production of Divided Metals; and I do hereby declare the follo\ving to be a full, clear, and exact description of the invention, such as will enable others skilled in the art 'to which it appertains to make and use the same.

If tungsten trioxid or tungstic acid or any other oxid, or a salt containing oxygen, be reduced to metallic tungsten by means of hydrogen, say by passing the hydrogen through a heated tube in which the raw material is placed, then right in front at the point where the hydrogen enters there will be found a very small nearly black layer which is chiefly composed of extremely finely divided tungsten still containing a little oxygen. Farther on in the tube there will be found partly metallic tungsten of a gray color, and also a quantity of incompletely reduced oxids, e. 9., the brown oxid. By strongly raising the temperature it is easily possible to reduce the whole to metal. In this case however the metal has a far greaterde-nsity and is less finely divided than the small black layer hereinbefore mentioned, and is materially lighter in color.

Exhaustive thermodynamic studies and investigations have shown it is possible to so' conduct the process that the nearly black and very fine product, which is obtained in Very small quantities only by the before stated method, shall be the prlncipal or exclusive product. For this purpose the current of hydrogen .lam p filaments.

must be employed in pro- 'ing carbon,

nary ether for example while still in the tube. After evaporation of the ether the product remains unaffected by air. The hydrogen which is used in very large excess is of course not lost butcan be used again, it being understood that after the water or steam produced during the process is removed, the hydrogen again becomes available for further use. This may be accomplished, for instance, 'b placing a complratively large number of reduction vessels in series between which the steam formed is removed, cit-her by drying agents or by cooling down.

, Any means which prevents steam from mlxlng with the reaction mixture in comparatively large quantities is suitable for obtaining tungsten of the quality above mentioned. For example in the reaction vessels and next the material to be reduced may be placed metallic magnesium which immediately decomposes the steam'and formshydrogen again.

The improved process described is not only applicable for metallic tungsten but also for metals of a similar kind, e. g. molybdenum.

The product obtained according to the method described is in consequence of its fine state of subdivision an excellent raw material for all kinds of purposes particularly for the manufacture of incandescent The small quantity of oxygen which it mostly contains is not injurious.

The reduction can be carried out not only by, means of hydrogen but also for example by means of methyl alcohol vapor or other gases or vaporous reducing agents contamalways with the precaution that 40 fuse quantity, that is to say for example, the higher oxidized products must neverextwentyfold in, excess of that actually reert anappreciable part al pressure. quired, so that the steam produced during What I claim is the reaction has only a very small partial 1. A process for producing finely dlvlded 45 pressure. Under these conditions, the reactungsten whlch consists 1n reducing oxygen tion, (which if the .reaction products are compounds of tungsten by.means of a very able to mix with the hydrogen in comparatively large quantities, only takes place at a strong red heat or yellow heat), proceeds even at a very weak red heat, and at this low temperature a final product is obtained, which, as already mentioned, is in an extraordinarily fine state of subdivision. The product is mostly spontaneously inflammable or pyrophoric, however, mabilit y spontaneous inflamdisappears sometimes of itself, but

large excess or profuse quantity of gaseous gen compounds of tungsten at a relatively low reducing temperature to the action of a current of a gaseous reducing agent of much greater volume than required to accomplish reduction of the oxygen compound of tungsten.

5. A process for producing finely divided tungsten which consists in subjecting oxygen compounds of tungsten to the action of a gaseous reducing agent causing a reaction between them and then depriving the resulting product of its pyro horic properties.

6. A process for pro ucing finely divided tungsten which consists in subjecting oxygen compounds of tungsten to the action of a gaseous reducin agent causing a reaction between them an then treating the resulting product with ether to deprive it of its pyrophoric propertles.

7. A process for producing finely divided tungstenwhich consists in treating oxygen compounds of tungsten with gaseous reducing agent and simultaneously eliminating the products of the reaction to prevent them from affecting it. e

S. A process for producing finely divided tungsten which consists in reducing compounds of tungsten with a suitable agent to metal in a finely powdered uniform condition, and treating the resulting product to render it stable upon exposure to air, while maintaining, unaltered, said finely powdered uniform condition.

9. As a new article of manufacture, 1neta1-"- lictungsten in the form of very fine nearly black powder without any material admixture of other tungsten substances.

10. As a new articleof manufacture, metallic tungsten in the form of very fine nearly black powder, stable upon exposure to atmospheric air. i

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

FRITZ BLAU.

Witnesses HENRY HASPER, WOLDEMAR HAUPT. 

